1. Field of the Invention
This invention relates, generally, to bailers. More particularly, it relates to a bailer that has a valve support and aligner assembly that is snapped into place at a lowermost end of the bailer. It also relates to a bailer having improved means for high speed insertion and improved means for preventing leakage.
2. Description of the Prior Art
Bailers are elongate cylindrical tubes that are lowered into container-held liquid fluids, natural bodies of water, and the like for the purpose of taking a sample of the liquid fluid so that laboratory tests can be performed thereon.
In the industry standard bailer, a free-floating ball valve at the lower end of the bailer unseats from its valve seat when the bailer is lowered into a liquid fluid, i.e., as liquid fluid flows upwardly into the hollow interior of the bailer. The ball valve sinks into seating relation to its valve seat when the liquid fluid stops flowing into the bailer. When properly seated, the ball valve should substantially prevent leakage of the liquid fluid from the hollow interior of the bailer.
In practice, however, the ball valve sometimes leaks profusely. The clothing of the person carrying the bailer to a vehicle that will transport the collected sample to a lab often gets wet as the liquid fluid within the bailer leaks past the ball valve. If the liquid fluid is an acid or other irritant, the leakage is more than a mere nuisance. Even if the liquid fluid is just water, the loss of sample is undesirable.
The seat for the ball valve is an annular step formed on an interior surface of a frusto-conical wall that provides a taper that interconnects the main body of the bailer with a reduced diameter downspout at the lowermost end thereof. A single grain of sand on the annular step can defeat proper seating of the ball valve. Sand particles and other particulate matter are commonly found in the liquid fluids that are collected by bailers in the field.
Moreover, leakage can occur due to manufacturing imperfections that cause the seating to be less than perfect, even when no particulate matter is present.
Since the ball valve is free-floating, it rises upwardly within the bailer as liquid fluid enters the bailer, there being no restriction that keeps the ball valve from such upward travel. After the upward flow of liquid fluid has ceased upon filling of the bailer, it takes several seconds or more for the ball valve to sink back to its valve seat at the lower end of the bailer. The ball valve sinks in water because its specific gravity is one or greater.
Thus, there are two time periods where the user of the bailer has to wait. First, the user must wait while the bailer sinks into the water or other liquid fluid and fills itself. Next, the user must wait for the free-floating ball valve to sink so that it returns to its seat. These waiting periods add up to a considerable amount of time when many samples are being taken. If the samples are being taken in hostile climates, such as polar regions, then the waiting periods are even more undesireable.
An improved bailer, more fully disclosed in the first incorporated disclosure, includes a valve seat in the form of an annular concavity formed in an interior surface of a lower part of the bailer. The lower part includes frusto-conical sidewalls. The annular concavity is configured to substantially match an exterior surface of a hemispherical valve body so that substantially no leakage of liquid fluid from the hollow interior of the bailer occurs when the hemispherical valve body is seated in the annular concavity.
The means for supporting and aligning the valve body in the first incorporated disclosure includes a spider positioned in the lower part of the bailer. The spider structure includes a plurality of legs of equal length that radiate from a hub at the center of the structure. The respective radially outermost ends of the legs are riveted or adhered to the inner sidewall of the bailer.
A central aperture is formed in the hub for slideably receiving a valve stem from which the valve body depends. In this way, the valve stem is coincident with the longitudinal axis of symmetry of the bailer, ensuring that the valve body is in proper alignment with its valve seat. The spider also limits upward travel, i.e., travel of the valve body away from the valve seat, so that the time required for the valve body to return to the valve seat is reduced.
The bailer of the first incorporated disclosure includes no means for positively locating the spider during assembly of the bailer. Instead, the assembler positions the spider in what appears to be an operable position, and secures the spider into said position by using an adhesive, rivets, or other fastening means.
The bailer of the first incorporated disclosure also includes no means for overcoming jamming problems caused by particulate entry into the central aperture formed in the hub of the spider. As a result, the valve stem may become stuck in its fully open or closed position, or any position therebetween, rendering the bailer inoperable, when sand or the like becomes wedged between a wall defining the periphery of the central aperture and the valve stem.
Nor is the spider member of the first incorporated disclosure designed to conserve materials or to speed the seating of the valve body after a sample has been taken.
The bailer of the second incorporated disclosure includes weighted members mounted to the leading and trailing ends of the bailer on an exterior surface thereof. These externally-mounted weights do not cause turbulence in the fluid being sampled as do internally-mounted weights. However, the weights are quite expensive and although they provide very fast insertion, they do not present an aerodynamic contour and thus their insertion speed is less than optimal.
It was not obvious to those of ordinary skill in this art how an improved means for positively positioning the spider and hence the valve body within the bailer could be provided, in view of the art considered as a whole at the time the present invention was made. Nor was it obvious how to overcome the jamming problem associated with particulate entry into the central aperture of the spider hub, or how to construct the spider in a way that would conserve materials. Moreover, it was not obvious how the cost of weighted bailers could be decreased and it was also not obvious how the bailer insertion speed and valve body seating speed could be increased.
The long-standing but heretofore unfulfilled need for an innovation that overcomes the limitations of the prior art is now met by a new, useful, and non-obvious invention. The present invention includes a substantially leak-free valve assembly for admitting liquid fluid into the hollow interior of a bailer as the bailer is lowered into a liquid fluid and for retaining liquid fluid within the hollow interior when the bailer is lifted from the liquid fluid. The novel assembly also provides externally-mounted inexpensive weights that are covered by an aerodynamically designed shroud to maximize insertion speed. In another embodiment, a weight housing, like the spider, can be snapped into position or otherwise attached to the leading end of the bailer.
The bailer is of the type that has an elongate cylindrical main body and a preferably separately-formed lower part or valve housing that is press fit or otherwise secured to the elongate cylindrical main body at its lowermost end. The valve housing has three parts that are integrally formed with one another. The first part is formed by cylindrical sidewalls and includes an annular shoulder formed on an external surface thereof that abuttingly engages the lowermost end of the elongate cylindrical main body of the bailer. The second part depends from the first and is formed by diameter-reducing frusto-conical sidewalls. The third part depends from the reduced diameter end of the second part and is formed by cylindrical sidewalls that form a downspout.
A valve support and alignment means in the form of a spider member spans a hollow interior of the first part of the valve housing. An annular shoulder formed on an interior surface of said first part provides a support means for the spider. The spider includes a central hub having a central aperture formed therein. The axis of symmetry of the central aperture is substantially coincident with a longitudinal axis of symmetry of the bailer. The central aperture slideably receives the valve stem from which a valve body depends and thus aligns it with the longitudinal axis of the bailer.
In a first embodiment, four legs of equal length radiate outwardly from the central hub and the respective outermost ends of the legs are equidistantly and circumferentially spaced apart from one another. Thus, the legs collectively form a xe2x80x9c+xe2x80x9d or cruciform configuration when viewed in plan view. An annular ring interconnects the outermost ends of the legs. In a first variation, the annular ring overlies the annular shoulder formed in the interior surface of the first part of the valve housing to positively position the spider. In a second, preferred variation, a thin, flange encircles the annular ring and the thin flange overlies the annular shoulder. A flexible and resilient annular ridge is formed in parallel, vertically spaced apart relation to the annular shoulder. The spacing is about the thickness (longitudinal extent) of the annular ring in the first variation and is about the thickness of the thin flange in the second variation. In this way, the spider is snap fit into place and no adhesives or. other fastening means are required to secure it into its operative position.
In a second, preferred embodiment, four legs of common length radiate outwardly from the hub, with the legs being grouped into two pairs of legs where each member of a first pair is substantially closer to the other member of the first pair than it is to either leg of the second pair. An arcuate segment interconnects the radially outermost ends of the legs of each pair, and the radially outermost ends of legs of different pairs are not interconnected, thereby saving materials.
In a first variation of the second embodiment, the arcuate segments overlie the annular shoulder formed in said interior surface. In a second, preferred variation a thin flange is formed along the extent of each arcuate segment, and said thin flange overlies said annular shoulder to provide the positive positioning means. The flexible and resilient annular ridge of the first embodiment is also provided in both variations of this second embodiment, for the same reason.
In both embodiments, the peripheral walls of the central aperture are fluted to overcome the problem caused by particulate matter accumulating in the central aperture of the spider hub.
Moreover, in both embodiments a hemispherical-in-configuration valve body having a hollow or solid construction is secured to a lowermost end of the valve stem, and that valve stem is slideably received within the central aperture formed in the spider hub as aforesaid. Accordingly, the hemispherical valve body rises and falls as liquid fluid flows into and out of the hollow interior of the bailer, respectively. The valve stem and the central aperture of the spider hub cooperate to maintain the hollow hemispherical valve body in substantial coincidence with the longitudinal axis of symmetry of the bailer as the hollow hemispherical valve body rises and falls. Moreover, the spider limits the distance the hemispherical valve body can travel away from to its valve seat.
The hemispherical valve body is made of plastic materials, preferably, having a specific gravity less than one so that said valve body floats on the surface of water if unrestricted. For liquid fluids other than fresh water, the specific gravity of the hemispherical valve body is adjusted as required so that it floats on the surface of the liquid fluid. The hemispherical valve body unseats from its valve seat more quickly than conventional ball valves when liquid fluid enters the bailer, because conventional ball valves have a specific gravity greater than one so that they can sink into their valve seat. The novel hemispherical valve body is returned to its seat not by sinking under its own weight but by the pressure of the water column above it. Being of hemispherical form, its trailing side is flat or concave, depending upon whether it is solid or hollow, respectively. Thus, the pressure of the water column returns it to its seat. A ball valve, on the other hand, has a spherical trailing side and the pressure applied by the water column is deflected and contributes little to the return of the valve body to its seat. Accordingly, the specific gravity of a spherical valve body must be one or greater so that it sinks into its valve seat under its own mass and not in reliance upon the pressure of the water column above it.
In both embodiments of the novel bailer, a valve seat in the form of an annular concavity is formed in an interior surface of the frusto-conical sidewalls. It is configured to substantially match an exterior surface of the hollow hemispherical valve body so that substantially no leakage of liquid fluid from the hollow interior of the bailer occurs when the hollow hemispherical valve body is perfectly seated against the annular concavity.
In one embodiment, the novel, inexpensive weight members at the leading end of the bailer are provided in the form of individual, central apertured bushings that are slidingly engaged on the downspout. The novel shroud is cylindrical in configuration and has a trailing end that slideably receives the cylindrical sidewalls of the first part of the valve housing. The novel shroud has a leading end adapted to be snap-fittingly engaged by an aerodynamic nose cone or cap that seals against the downspout to prevent liquid fluid entry into the shroud and that maximizes insertion of the bailer into the liquid fluid being sampled.
In another embodiment, the weight is provided by even less expensive materials, such as sand. The sand is poured into the space defined between the shroud and the valve housing and the novel cap is used to maintain the sand in said space. Alternatively, a measured amount of sand, such as two ounces, four ounces, etc., is placed into a small, elongate sand bag and that small, elongate sandbag is positioned into encircling relation with the downspout and housed by the shroud and the cap.
In yet another embodiment, use of the shroud is eliminated and a highly novel weight housing is provided. The novel weight housing can hold loose sand, a sand bag, or other inexpensive weight means. It is designed to snap onto the valve housing, preferably at its leading end to the downspout and at its trailing end to the frusto-conical walls of the valve housing. This eliminates the shroud and enables a customer order to be filled by snap fitting a weight housing of a known weight onto the valve housing in a negligible amount of time.
It is a primary object of this invention to provide an improved valve structure for bailers.
A more specific object is to advance the art of bailer manufacturing by providing a structure for positively positioning a spider and hence the valve means of a bailer.
Another object is to provide a spider structure that conserves materials.
Still another object is to provide a valve structure for bailers that reduces jamming of the valve structure by particulate matter.
Yet another object is to improve high speed insertion of bailers by making them less expensive and by enhancing their aerodynamic profile.
These and other important objects, features, and advantages of the invention will become apparent as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.